1. Technical Field
The present invention relates to a rubber composition for a tire and a pneumatic tire using the rubber composition.
2. Related Art
Conventionally, it is proposed in a rubber composition for a tire to add various additives in order to reduce rolling resistance of a tire and improve low fuel consumption. For example, JP-A-2004-204176 proposes to add cyclodextrin or sucrose, and a sulfur-containing silane coupling agent to a rubber composition containing a diene rubber mainly comprising styrene-butadiene rubber for the purpose of the improvement of wet performance and the reduction of rolling resistance.
Thus, it has been conventionally known to add a saccharide to a rubber composition, but it has not been known to add sucrose benzoate or sucrose acetate to a rubber composition.
JP-A-2010-031261 proposes a rubber composition for a tire comprising specific diene rubber having added thereto a tea extract together with specific carbon black and silica in order to improve abrasion resistance without deterioration of rolling resistance performance. This patent document discloses sucrose fatty acid ester as a surfactant for treating the extract, but does not disclose sucrose benzoate or sucrose acetate.
JP-A-11-343302 discloses a leather-like composition for automotive interior in which a sucrose derivative such as sucrose benzoate is used as a plasticizer added together with polyvinyl chloride and a rubbery polymer. However, this patent document does not relate to a rubber composition for a tire. Furthermore, in this patent document, an acrylate elastomer is used as the rubbery polymer, and it is not disclosed to use a diene rubber. Therefore, this patent document does not disclose to combine a sucrose derivative with a diene rubber and a reinforcing filler.